1. Field of the Invention
The present invention relates to an optimum resource allocation method and system in medium access control (MAC) of distribute scheme in a wireless personal network (WPAN), and more particularly, to a method and system for optimizing resource allocation by determining the number of medium access slots (MASs) needed to prevent waste of wireless resources.
This work was supported by the IT R&D program of MIC/IITA [2006-S-071-01, Development of UWB Solution for High Speed Multimedia Transmission]
2. Description of the Related Art
Wireless personal area network (WPAN) is a technology that enables wireless connectivity between devices such as audio/video devices, computers, and peripheral devices within about 10 meters and supports communication between portable small-sized (multimedia) devices with a lower power so as to support various services.
In medium access control (MAC) of WiMedia Alliance, which is distributed MAC in the WPAN, each of devices DEVs basically transmits its own beacon frame, analyzes beacon frame information on neighboring devices to control basic timing between the neighboring devices, and distributes quality of service (QoS), a hibernation mode, and security in order to operate itself.
The MAC in the WPAN has a superframe structure. The superframe includes a beacon period (BP) and a data period (DP). The BP includes beacon time slots (BTSs) in units of 85 μs, and the DP includes medium access slots (MASs) in units of 256 μs.
Unlike a scheme in which network management is centralized by a specific device, in the existing MAC, network management is performed by each device, so that network construction is easily performed in a wireless environment in which devices are frequently connected and disconnected. A network in which each device is connected to neighboring devices is illustrated in FIG. 2. Each device selects a BTS which is not used from among a number of BTSs and transmits its own beacon frame. The beacon frame of each device includes device (DEV) identifier (ID), BTS information about the device, medium usage information, and the like.
In addition, the devices negotiate with each other to reserve MASs of the DPs by using information elements (IE) in the beacon frames in the BPs or command frames in the DPs, so that competition and collision of transmitted data in the DPs can be prevented.
However, the existing MAC has problems in that each device has to analyze a large amount of information on the neighboring devices, and it takes much time to search for a point of compromise and this may cause waste of resources. Moreover, if not all of the devices have mechanisms of optimally allocating necessary wireless resources, the wireless resources in the entire wireless personal area network may be wasted severely.